I know this question is not quite related to Dynamo perhaps, but I suppose Dynamo forum is more vocal than MEP forum, so I decide to put it here since didn’t get much attention back there.
It is really bothering.
Here’s my situation. Our team mainly uses data from CIBSE to calculate pressure drop for duct fittings. What Revit has are: built-in ASHRAE table, Specific Loss, Specific Coefficient and Not Defined. It pretty much leads me to Specific Loss / Coefficient. So I thought about maybe I can map data from CIBSE to the fittings onto these two options via Dynamo or some API calls later. But I found that some of the fittings does not even have these options under loss method. At first, I thought I was just dealing with few bugsy duct fitting families. But it turns out Revit Sample project has it too, some of them have just only ASHRAE and Not Defined.
I found some discussion saying this issue exists in previous versions. Some found Revit wiped out these two options in Revit 2017. I cant say much about Revit 2017 but I’m experiencing it in Revit 2019.
Really need some help on it. Any suggestion would be appreciated.